Furnace Making Clicking Noise While Running? (Ways to Fix It)

Ryan Womeldorf
by Ryan Womeldorf

Your central heating system, when working properly, keeps your home nice and warm even during the most frigid of temperatures. When something goes wrong and that heater stops working, it can cause major inconveniences for you and your family.

A furnace can click while running if the gas valve is clogged or if the ignitor and pilot light fails. The thermocouple flame sensor can also cause a furnace to make a clicking noise while running if it is damaged. Clicking noises can also indicate electrical problems or a problem with the gas supply in your furnace.

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Clicking but Your Heat Works Normally

It may seem like your heating system is working just fine except for that clicking noise. This could be indicative of a potential issue with the bearings. The bearings located in the main furnace blower or the inducer blower can be the cause. You can hear when those components become clogged or when the bearings have worn out.

1. Inspect the bearings. The bearings that are on the main blower motor could be clicking due to the shaft being dirty or potentially rusted.

2. Clean and lubricate. Make sure that you not only clean but lubricate the fan shaft in order to both fix the problem and prevent further excessive wear and tear.

3. Replace the bearings. When the bearings wear out, it can cause the motor to burn out entirely if you don’t replace them in due time. So, if you hear a clicking noise consistently, don’t just ignore it.

The Inducer Fan

Another reason that you might hear clicking despite the furnace heating properly could be due to the inducer fan. You would generally only find the inducer fan in oil furnaces, but the inducer can become loose over time, wearing down with frequent use. Furthermore, you may notice that there is a buildup of dust on the blades.

In most cases, you can quickly clean the blades or repair the loose or damaged inducer fan on your own. When in doubt, it is always a good idea to bring an HVAC technician out to take a look at the problem for you.


Finally, if your furnace seems to be working normally but you still hear a consistent clicking noise, it could be the ductwork. This could be somewhat easier to hear because it will come from various points of the home as opposed to coming from the furnace directly.

Cracking, clicking, or popping coming from random parts of your house is an indication that you may have loose or cracked ductwork. Depending on the severity of the issue, you may be able to implement a quick fix but will more likely need an HVAC technician to come out and perform maintenance or repairs.

Furnace Clicking but Not Working

While there are a couple of things that can cause the furnace to click while still providing normal heating, you may find yourself hearing clicking coming from the furnace without any heat coming out. This could be indicative of several issues. They will require further troubleshooting to not only locate the issue but to implement a fix.

Flame Sensor

The first reason that your furnace may be clicking but not turning on or functioning normally is due to the flame sensor. Furnaces come equipped with a thermocouple flame sensor; this is meant to work as a safety measure.

The thermocouple reacts to any abnormal flame temperatures and automatically shuts off the gas. This can be the clicking sound that we hear and can also be why it continues for some time.

Troubleshooting the Flame Sensor

Should the furnace start to click, and you notice the blower turning on and off, it could indicate that the flame sensor is faulty.

It is advised that you leave any of the flame component issues to a professional HVAC technician, though you could always follow the user manual of your specific model if need be.

Pilot Light Issues

One of the components that are likely to wear down consistently over time is the pilot light. Think about it like this: for several months per year, your furnace is running day after day and in some instances, the entire day.

1. Inspect the pilot. With years of work behind it, the pilot light assembly can either start to loosen, get clogged up, or could wear out entirely.

2. Replace if necessary. When you hear clicking in your furnace but there is no heat, it could be indicative of the pilot light malfunctioning.

Malfunctioning pilot lights are relatively simple even for amateurs, but make sure to consult the user manual for that specific model if you have any questions about how to potentially fix the pilot light.


Another reason that your furnace may be clicking yet not turning on entirely could be due to a potential issue with the ignitor. Much like a gas stove, the furnace clicks whenever it fires up. If you notice that the furnace just keeps clicking and never ignites, there are a number of potential issues in front of you.

Ignitor Repairs are for the Pros

While the pilot light is a more common issue, the ignitor is not to be overlooked. If there is not loose wiring around the ignitor, it could be that the component itself has become clogged or potentially damaged over time.

It is important that you leave ignitor repairs or replacements to the professionals. A small mistake could be potentially dangerous, leading to a gas leak or even fire.

Gas Supply Problems

Should you notice that your furnace is clicking repeatedly but isn’t working as it should, it could be a potential gas issue. In this case, the gas is unable to successfully reach the pilot light and the ignitor will simply keep clicking in an effort to spark the flame.

While it may seem like an inconvenient issue, it could also potentially indicate a serious gas leak or even a clogged gas valve. You might even hear irregular clicking sounds emanating from the gas valve, which could indicate that the unit has insufficient voltage. This could be due to bad thermostat controls or faulty gas meter controls.

1. Check gas flow. Should your furnace start to run before shutting off in short order, it will be indicative of the inconsistent flow of gas.

2. Consult a pro. When it comes to potential gas problems, do not handle the issue yourself. Gas issues are potentially dangerous and should always be handled by a professional HVAC technician.

Gas Valve

Somewhat similar to potential gas supply issues is a problem with the gas valve. These valves can become clogged, jammed, or even broken. When that happens, it will fail to let the appropriate amount of gas out if any at all.

You can generally tell when the gas valve is bad because the ignitor will click over and over again. Think of it like someone trying to use an empty lighter. Gas valves should be replaced or repaired by a certified HVAC technician as gas-related problems are potentially dangerous.

Electrical Components

When you hear clicking coming from your furnace, but it won’t turn on, another issue could lay within the electrical components. Electric furnaces in particular have a number of elements that comprise the starter system.

The good thing here is that you don’t have to worry about a gas leak in this instance. The bad news is that you will hear constant clicking and your furnace won’t start up normally if at all. Electrical components can be a complicated fix, so it makes sense to call in a certified HVAC technician to resolve the issue.

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Sounds That You Should Not Ignore

Clicking or cracking noises might be somewhat common to hear. They can indicate potential issues with the furnace but might be nothing at all. There are, however, plenty of other sounds that you definitely do not want to ignore.


Buzzing is usually indicative of some kind of excessive vibration. When you have vibration in your HVAC system it is likely due to a loose component, more than likely a transformer. You can troubleshoot these issues to find the source of the problem, though repairs may or may not require a technician.


This particularly annoying sound is to let you know that there may be a belt or fan motor issue. Squealing is a sign that the fan motor or a belt is wearing down past the point of normal wear and tear.


You will normally hear this sound coming out of your HVAC system when there is a clog. More often than not, your filter will become overly dirty or clogged and required replacing. A good rule of thumb is to replace your furnace filter every 90 days or so. You want to keep the filter clean to allow your heating system to work more efficiently, run cleaner, and to perform quieter.


If you notice that your furnace is giving off a rattling noise, it could be an indicator that something is very loose. In a worst-case scenario, it could also be indicative of a broken fan or even broken motor parts.

A good rule of thumb is to take heed of any out-of-the-norm noises. After all, it is better to be safe than sorry.

Ryan Womeldorf
Ryan Womeldorf

Ryan Womeldorf has more than a decade of experience writing. He loves to blog about construction, plumbing, and other home topics. Ryan also loves hockey and a lifelong Buffalo sports fan.

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